The roles of the Neuropathology and Genotyping Core are to promote brain availability for research, and to extract DNA from peripheral blood samples and carry out genotyping at loci implicated in Alzheimer's disease (AD). Thus, the general aims include performing a thorough postmortem examination, harvesting as many samples as possible for research from each brain donated (Vonsattel laboratory), and accessioning blood samples, extracting genomic DNA, and carrying out PCR amplification and genotyping for APOE, TP73 and PDE4D single-nucleotide polymorphisms (SNPs) (Tycko laboratory). The specific aims of the Core are: - To establish an accurate diagnosis on all autopsy brains obtained for this project. - To prepare cryopreserved samples from defined anatomical regions of the brains according to standardized protocols. - To build a library of paraffin embedded tissue of precise brain areas from these same autopsy cases. - To extract genomic DNA from blood samples of AD cases and controls. - To perform PCR amplification and genotyping ofAPOE, TP73 and PDE4D SNPs. The Core will provide tissues and genotypes for project l (Dr. Mayeux), project 2 (Dr. Luchsinger), project 4 (Dr. Louis), and project 5 (Dr. Devanand).